Over the past decades, a great many electronic music controllers have been developed, but few approach the ubiquity of the plano-style keyboard. The keyboard's versatility and its large number of skilled performers ensure that it will maintain a prominent place in digital musical performance for the foreseeable future.
The keyboard is by nature a discrete interface; on acoustic plano as well as on most MIDI keyboards, notes are defined solely by onset and release, giving the performer limited control over their shape. Although certain MIDI keyboards are equipped with after-touch (key pressure) sensitivity, this arrangement tends to lack nuance and flexibility. On these keyboards, a key must be completely pressed before after-touch can be used, so after-touch cannot control articulation. After-touch is also difficult to use in rapid passage work, and control is limited to a single dimension. Though some keyboards also provide continuous control through external knobs, wheels or sliders, these lack the immediacy and expressivity of control through the keyboard itself.
It would therefore be beneficial to provide a keyboard that provides nuanced and flexible control of musical sounds from within the keyboard mechanism itself.